Solid state drives (SSD) require a backup power source to ensure that data can be safely written to cache and the SSD gracefully shuts down when the main power source becomes unavailable. SSDs often utilize a capacitor farm to provide backup power. Thus, a series of capacitors are often arranged on the same printed circuit board (PCB) as the flash memory. However, the capacitors required to provide sufficient backup power may occupy more space than is available on the PCB or may be taller than the other components and therefore require the PCB to be placed deeper within the drive enclosure to ensure the capacitors do not extend beyond the enclosure. This reduces the vertical space available on the side of the PCB opposite the capacitors.
Larger SSD enclosures, such as those having a 15 mm z-height, may not be impacted by the heights of the capacitors, which may be 4 mm. However, in smaller device sizes, such as 7 mm z-height, the heights of the capacitors occupy a larger portion of the available z-height. Replacing the tall capacitors with an increased number of shorter capacitors presents challenges to layout design. In addition, PCBs commonly used in SSDs cannot support capacitors mounted on both sides.